Red, green, and blue light-emitting diodes (LEDs), which are capable of realizing high brightness and white light, have been developed based on the development of a gallium nitride (GaN) metal-organic chemical vapor deposition and a molecular beam growth method, for example.
Such LEDs have excellent environmental friendliness because they include no environmentally harmful materials such as mercury (Hg), which has conventionally been used in lighting apparatuses such as incandescent lamps and fluorescent lamps, and also have other advantages, for example, a long lifespan and low power consumption. Therefore, existing light sources are being replaced with LEDs. A competitive core factor of LEDs is the realization of high brightness by high-efficiency and high-output chip and packaging techniques.
In order to realize high brightness, it is important to increase light extraction efficiency. Various methods using a flip-chip structure, surface texturing, a patterned sapphire substrate, a photonic crystal technique, an anti-reflection layer structure, and the like have been studied in order to increase light extraction efficiency.
FIG. 1 illustrates a plan view of a conventional light-emitting element 10.
The light-emitting element 10 illustrated in FIG. 1 includes first and second electrode pads (or bonding pads) 22 and 24, nine emission areas (or light-emitting cells) 40, and a connection metal 30 that electrically interconnects the neighboring emission areas 40. Here, due to the placement of the second electrode pad 24, the planar area of an active layer in a ninth emission area P9 is less than the planar area of an active layer in the other first to eighth emission areas P1 to P8. Due to this, the current density of the ninth emission area P9 may be greater than the current density of the other first to eighth emission areas P1 to P8. This may cause damage to the connection metal 30 that electrically interconnects the eighth emission area P8 and the ninth emission area P9, thus causing the light-emitting element 10 to be electrically opened, which may deteriorate the reliability of the light-emitting element.